Jet pipe cutter



J. H. KIRBY ll JET PIPE CUTTER July 18, 1967 2 Sheets-Sheet l Original Filed June 16, 1961 INVENTOR.

J. H. KIRBY JET PIPE CUTTER July 18, 1967 Original Filed June 16, 1961 2 Sheets-Sheet 2 /0/7/7 Mry, I

INVENTOR.

United States Patent 3 Claims. (Cl. 102-20 This application is a continuation of patent application Ser. No. 117,540, entitled, Jet Pipe Cutter, filed June 16, 19 61, and now abandoned.

This invention pertains generally to well apparatus and particularly to apparatus for detonating an explosive charge in a well bore.

Although apparatus for detonating explosive charges in well bores have been used, such apparatus has not provided positive operation and has left much to be desired in the way of adaptability to various operating conditions in the field.

During recent years, increased exploration and production activity in coastal areas have presented definite problems in proper utilization of existing perforating apparatus and other apparatus for detonating explosive charges in well bores. In coastal-area operation and in offshore-drilling operation, lightweight equipment has become a necessity due to limited transportation facilities. Prior to development of the device disclosed in the present invention, cumbersome equipment was necessary to detonate explosive charges in well bores. One reason for the cumbersomeness of equipment was the necessity of the multiple-conductor cable which was utilized in detonating the explosive charge. The present invention alleviates the need for such multiple conductor cable.

Also in devices known prior to the present invention, the controls for the electrical system for detonating an explosive charge in a well bore were located at the surface of the earth, thus making such devices complex and expensive. When the electrical system was an integral part of the explosive apparatus, the explosive charge was detonated through manipulation of control equipment which remained at surface level. Also known systems left much to be desired in the way of safety. The problems of high cost, complicated and cumbersome apparatus used for positioning and detonating an explosive charge in a well bore, and the danger of injury to personnel and equip ment when the explosive charge is inadvertently detonated are eliminated or minimized in the present invention.

Therefore, an object of the present invention is to provide improved apparatus for detonating an explosive charge in a well without appreciable damage to such apparatus, thereby permitting repetitive use.

Another object of the present invention is to provide a detonating device for explosives in a well bore, such detonating device being characterized by simplicity of component parts, ease of operation, safety, and positive action.

Yet another object of the present invention is to provide an improved method of detonating an explosive charge in a well bore. A further object of the invention is to provide apparatus for attaching a shaped explosive charge thereto for suspension on a flexible line in a well, such apparatus including a battery housing which provides electrical energy to detonate such charge.

In the drawings, 7 FIGURE 1A is a partial sectional, elevational view of the upper portion of the apparatus incorporating the invention, including a go-devil assembl FIGURE 1B is a partial sectional, elevational view of the middle portion of the apparatus utilized in the invention;

FIGURE 1C is a partial sectional, elevational view of the lower portion of the apparatus utilized in the invention;

FIGURE 1D is a cross-sectional, plan view taken along line 1D-1D of FIGURE 1C;

FIGURE 2 is a partial sectional, elevational view of the upper portion of the apparatus incorporating the invention;

FIGURE 3 is a cross-sectional, plan view taken along line 33 of FIGURE 1A; and

FIGURE 4 is a partial sectional, elevational view of the upper portion of the apparatus utilized in the invention showing such upper portion in unlocked position.

In practicing the invention, there is provided well apparatus including a tubular member adapted for coupling to an upper section which is adapted for coupling to a flexible line. Such upper section includes a shear plug through which the flexible line may be attached and a latch or releasing mechanism for releasing a battery housing disposed inside the tubular member. Resilient means disposed intermediate the battery housing and releasing mechanism impart thrust to the battery housing when it is released. Coupled to the lower portion of the tubular member is an explosive charge. When the apparatus has been lowered in a well to a preselected depth, a go-devil is dropped along the flexible line to cause the releasing mechanism of the well apparatus to unlock and thereby free the battery chamber for movement within the outer chamber. Resilient means impart movement to the battery chamber upon unlocking and the battery chamber is driven downwardly to contact and detonate the explosive charge. If the charge is not exploded within a short period of time, a safety device such as a fuse disables the electrical system so that the apparatus may be removed from the well without danger of exploding. No appreciable damage is incurred to the apparatus other than the explosive charge container thereby allowing the apparatus to be used again and again.

Referring now to the drawings in more detail, FIG- URES 1A, 1B and 1C taken together show a completely assembled well apparatus which comprises three main sections, namely, upper section 20 to which middle section 58 is coupled, and lower section 68. As shown, the three sections may be threadedly coupled together.

In practicing the invention, the assembled well apparatus is suspended from a flexible line 10 which may be wound on suitable spool apparatus at the surface of the earth. Utilization of a single conductor, flexible line such as steel is an important feature of the invention primarily because of its light weight and small size but other advantages will be explained forthwith.

Upper section 20 includes a shear plug 12 to which flexible line 10 is fastened. Upwardly from shear plug 12 is positioned a latch release plug 14 having a go-devil cushion 16 disposed therein. Intermediate the shear plug 12 and latch release plug 14 is release plug spring 32 which causes plug 14 to remain near the uppermost portion of section 20. Pivotally mounted on pin 26 are latch members 22 and 24 having fingers 34 and 36 which are normally in engagement with mandrel 38 having a head 40. An elastic ring 28 positioned on the outside of upper section 20 provides a holding force for retaining fingers 34 and 36 in engagement with head 40 while the release mechanism is locked. A similar elastic ring 15 acts as a retainer when the release mechanism is unlocked in a manner to be explained subsequently. Fishing wickers 18 are provided on the upper portion of upper section 20 to allow, the well apparatus to be fished out of a well bore with suitable known apparatus when necessary.

Middle section 58 of the well aparatus may be substantially tubular in structure and disposed therein is a battery housing 54. Mandrel 38 passes through aperture 39 and is threadedly engaged by threads 50 to battery housing 54. Resilient means which may be a spring 46 is disposed between shoulder 44 of the mandrel and shoulder 48 of upper section 28. When the head 46 is locked in position by the latch or release mechanism, spring 46 will be compressed.

Disposed in battery housing 54 is a battery contact spring 52 and a plurality of battery cells 56 which may be of the flashlight type. Battery housing 54 has contact springs 57 and 61 coupled thereto by fasteners 59 and 63 to provide ground contact between the housing 54 and middle section 58. In the lower portion of battery housing 54 is a fuse 60 which normally provides a conductive path for electric current from the battery cells to the contact 62. Contact 62 is insulated from the battery housing 54 by insulator 63. A safety pin 64 is disposed between contact 62 and member 66 of the firing head assembly of the lower section 68 while the well apparatus is assembled but out of the well.

Lower section 68 of the Well apparatus is coupled through threads 77 to the middle section 58. Member 66 is coupled through rod 67 and conductor 69 to detonator 72. Member 66 may be coated with a thin layer of suitable heat and electrical insulation material to eliminate shortcircuiting of the electrical circuit when the well apparatus is subjected to high temperature or acid environment in the well bore. Conductor 81 is a ground return for the electrical circuit from detonator 72. A resistor 70 is connected between conductors 69 and 81 and the function of resistor 70 will be explained subsequently. A metal contact washer 71 insures proper ground return through conductor 81. O-rings 83, 73, and 75 provide sealing for components of the firing assembly in lower section 68.

Adjacent detonator 72 is a booster material 74 which is joined to a suitable flexible cord-type explosive 76. Explosive 76 may be Primacord, such as that manufactured by the Ensign-Bickford Company, Simsburg, Conn., and which is composed of a hollow fabric or plastic tube filled with one of the well-known detonatable chemical explosives such as pentaerythritoltetranitrate. Such Primacord is disposed in a steel housing 78 which is coupled to lower section 68 through threads 93. O-ring 85 provides sealing between lower section 68 and steel housing 78.

Disposed in air chamber 82 is aluminum tube 80 which extends partly into explosive charge 86. Explosive charge 86 is normally contained in an aluminum housing 84 having a shaped, unitary copper cone 88. Such cone provides explosive pressure in the recess 91 of steel housing 78 to cause a cutting or severing action. Aluminum cap 90 is positioned on the lower portion of steel housing 78 and O-ring 92 provides sealing between the cap and housing.

Thus in the embodiment of the invention disclosed in FIGURE 1C, the shaped explosive charge is of the type utilized in severing pipe or tubing and is known as a cutting jet charge. Such charge is available from the Byron- Jackson Division of Borg-Warner Corporation. It should be apparent, however, that the well apparatus of the present invention may be utilized to detonate explosive charges of various configurations and types.

FIGURE 1D shows the charge configuration in a plan view.

FIGURE 2 is a partial sectional, elevational view of a portion of the upper section of the well apparatus taken along line 2-2 of FIGURE 1. FIGURE 2 shows screws 96 and 98 positioned in recesses 97 and 99, respectively, of shear plug 12. Thus in instances when the well apparatus is stuck and excessive tension is put on the flexible line, such tension will cause shear plug 12 to become unseated from screws 96 and 98 before the line will break. Thus, line 10, plug 12, spring 32, and latch release plug 14 are removed as shear screws 92 and 94 are severed by movement of the plug 14 past slots (not shown) in the upper port of upper section 20. Thus it is apparent that 4 line 10 may be removed when the well apparatus is stuck in the hole without breaking the wire line and thereby necessitating fishing for the line left in the hole. After the line is pulled from the hole, a conventional fishing tool may be used to engage wickers 18 and remove the well apparatus from the hole.

Collar locator springs 104 and 106 are coupled to upper section 20 by screws 100 and 102. Collar springs 104 and 106 serve to locate collars in a string of pipe or tubing thereby assuring that the explosive charge will not be detonated adjacent a collar and thereby fail to sever the pipe.

FIGURE 3 taken along lines 33 of FIGURE 1A shows safety clip 30 positioned on upper section 20 to prevent inadvertent unlocking of the latch mechanism through movement of latch members 22 and 24 while the well apparatus is not in a well.

FIGURE 4 shows the latch or release mechanism in an unlocked or released position whereby the explosive charge of the well apparatus is detonated. As stated previously, the well apparatus may be assembled at the well site and as such apparatus is lowered into the well on line 10, seafety pin 64 is removed. As the well apparatus is lowered farther into the well, safety clip 30 is removed and the Well apparatus is suspended at the desired depth. After positioning the apparatus in the well with the collar locator springs, a go-devil comprising a bull plug 108, a body 110, and a neck member 112 is engaged with line 10 and dropped along the line 10 into the well. As gravity provides impetus to the go-devil, bull plug 108 soon contacts cushion 16 of latch release plug 14 and fingers 34 and 36 are pivotally opened thereby freeing mandrel 38. Elastic rings 15 and 28 restrict the pivotal movement of the latch members, as may be seen in FIGURE 4.

Upon release of the latch or release mechanism, spring 46 imparts thrust to battery housing 54 thereby causing the head 40 of mandrel 38 to pass through aperture 39. Battery housing 54 is thus moved inside of the tubular member so that contact 62 engages member 66 to initiate detonation of the explosive charge to sever pipe 114. If the member 66 has been coated with a thin layer of insulating material, such layer is pierced by the downward movement of the battery housing 54. If a malfunction occurs so that the explosive charge is not detonated within several seconds, resistor 70 provides a load and electric current is drawn tthrough the electrical circuit. After several seconds of current conduction, fuse 60 melts and opens the electric circuit. Thus the danger of inadvertent detonation of the explosive charge is minimized so that the well apparatus can be pulled from the hole in relative safety.

If the explosive charge is detonated properly, only the steel housing 78 of the well apparatus will be destroyed and other components may be used again.

Thus, the invention provides an improved apparatus and method for detonating explosives in a well. Such apparatus affords safety, simplicity, positive action, and compactness and may be used for severing pipe or tubing through a single or plurality of detonations. The improved method of detonation is simple and safe.

Although a preferred embodiment of the invention has been shown and described, it should be understood that the scope of the invention is to be determined by the following claims.

I claim:

1. Apparatus for detonating an explosive charge in a well, said apparatus including in combination,

a cyclindrical housing adapted to be coupled to the end of a flexible line and lowered into the well,

explosive means coupled to the lower portion of said cylindrical housing,

actuating means disposed within said cylindrical housing, said actuating means including latch means having an elongated body with an upper and lower taperture, a plug member disposed in said upper aperture and having' tapered surfaces, first and second latch members pivotally mounted in said elongated body, each said latch member having a tapered upper edge for slidable contact with the tapered surfaces of said plug member, said latch members providing a restricted aperture near the lower portion thereof, and resilient means disposed intermediate the pivot point of said latch members and said plug member to position said plug member away from the pivot point whereby movement of said plug member toward the pivot point will provide pivotal movement of said latch members thereby increasing the volume of the restricted aperture, and

a go-devil slidably engaged with the flexible line for actuation of said actuating means within said cylindrical housing to provide detonation of said explosive means at any selected location in the well.

2. Apparatus for use in a well, said apparatus including in combination,

a cylindrical housing adapted to the coupled to the end actuating means disposed within said housing, said actuating means including a battery housing having an elongated body, latch means having an elongated body with an upper and lower aperture, a plug member disposed in said upper aperture and having tapered surfaces, first and second latch members pivotally mounted in said elongated body of said latch means, each said latch member having a tapered upper edge for slidable contact with the tapered surfaces of said plug member, said latch members providing a restricted aperture near the lower portion thereof, and resilient means disposed intermediate the pivot point of said latch members and said battery housing to position said battery housing away from the pivot point whereby movement of said plug member toward the pivot point will provide pivotal movement of said latch members thereby increasing the volume of the restricted aperture to move said battery housing away from the pivot point.

References Cited of a flexible line and lowered into the well,

actuating means disposed within said cylindrical hous- UNITED STATES PATENTS ing, said actuating means including latch means hav- 1 325 17 9 1 31 Collom et 1 294 113 ing an elongated body .With an upper and lower 2,1 7,007 1 1940 Barnes 1 65 X aperture, a plug member disposed in said upper aper- 2 197 07 4 1940 McKinley 1 12g ture and having tapered surfaces, first and second 2 202 337 1940 1 1 175 4,5 latch members pivotally mounted in said elongated 2 3 2 2 9 5 Kaveler et 1 16 3 X body, each said latch member having a tap re 2,39 ,7 3 3 194 Ahrgren 175 4 55 upper edge for slidable contact with the tapered sur- 2 7 377 9 7 Zschokke 1 5 X faces of said plug member, said latch members pro- 2,595 15 5 1952 s t 102 20 viding a restricted aperture near the lower portion 2 1 122 1952 McKinley 175 4 56 X thereof, and resilient means disposed intermediate 2,620,029 1 52 Turechek et 1 1 5 X the pivot point of said latch members and said plug 2 21 732 12 1952 Ahlgren 175 4 55 member to position said plug member away from the 7 5 2 4 1955 Kanady 175 4 5 X pivot point whereby movement of said plug member 2,748,660 195 Spencer 175 4,54 toward the pivot point will provide pivotal move- 2 7 727 9 195 Moore 294.41 ment of said latch members thereby increasing the 2 7 343 3 1959 Huber 175 4 56 volume of the restricted aperture, and 2 9 1 909 11 1959 Fuchs 1 3 a go-devil slidably engaged with the flexible line for 2,978,023 4 19 1 Webb 1 3 moving said plug member toward said pivot point 57 2 5 1 2 Christopher 175 4 to increase the volume of the restricted aperture of said latch members at any selected location in the well. 3. Apparatus for use in a well, said apparatus including in combination,

a housing adapted to be coupled to the end of a flexible line and lowered into the well, and

CHARLES OCONNELL, Primary Examiner. ERNEST R. PURSER, Examiner.

I. A. CALVERT, Assistant Examiner, 

3. APPARATUS FOR USE IN WELL, SAID APPARATUS INCLUDING IN COMBINATION, A HOUSING ADAPTED TO BE COUPLED TO THE END OF A FLEXIBLE LINE AND LOWERED INTO THE WELL, AND ACTUATING MEANS DISPOSED WITHIN SAID HOUSING, SAID ACTUATING MEANS INCLUDING A BATTERY HOUSING HAVING AN ELONGATED BODY, LATCH MEANS HAVING AN ELONGATED BODY WITH AN UPPER AND LOWER APERTURE, A PLUG MEMBER DISPOSED IN SAID UPPER APERTURE AND HAVING TAPERED SURFACES, FIRST AND SECOND LATCH MEMBERS PIVOTALLY MOUNTED IN SAID ELONGATED BODY OF SAID LATCH MEANS, EACH SAID LATCH MEMBER HAVING A TAPERED UPPER EDGE FOR SLIDABLE CONTACT WITH THE TAPERED SURFACES OF SAID PLUG MEMBER, SAID LATCH MEMBERS PROVIDING A RESTRICTED APERTURE NEAR THE LOWER PORTION THEREOF, AND RESILIENT MEANS DISPOSED INTERMEDIATE THE PIVOT POINT OF SAID LATCH MEMBERS AND SAID BATTERY HOUSING TO POSITION SAID BATTERY HOUSING AWAY FROM THE PIVOT POINT WHEREBY MOVEMENT OF SAID PLUG MEMBER TOWARD THE PIVOT POINT WILL PROVIDE PIVOTAL MOVEMENT OF SAID LATCH MEMBERS THEREBY INCREASING THE VOLUME OF THE RESTRICTED APERTURE TO MOVE SAID BATTERY HOUSING AWAY FROM THE PIVOT POINT. 